At exactly 1000 RPM (10 mph?) - just barely touching the throttle I have pulsing surge. It just kind of bucks a little bit until I speed up or slow down. It does not do this below or above 1000 RPM. Car runs fantastic otherwise. Plugs, MAF, Filters all new and this symptom before they were replaced.
Any ideas? Is it a fly by wire characteristic/issue?
Sounds like your system is on 'Limp Mode' - Do a reset it should be okay. Also what's the Year and model of your car?
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Its a 2000 E55 AMG - I live in Atlanta - It has 65k miles.
Reset doesn't fix it. I may not understand limp mode but the car shifts fine and the check engine light has never been on.
This "pulse" is only perceptible driving in the parking lot at 1000 RPM's - about 8-10 mph. If I give it bit more throttle to 1200 RPM's on it goes away and is smooth as silk.
I bet you a cat or the cats are going. does it feel like if you go up to about 2000 rpms at say 30mph it takes a noticable amount of time to come back down. could be clogged cats if so. cats also would explain surging. Id have it checked out. When the cats went in my E50 there was a symptom of the car acting like a manual transmission surging and bucking (not hard), like when you floor it and let up at low speed in a manual.
Othe possibility is some sort of EGR problem, maybe a vacuum leak in the emissions system.
I bet you a cat or the cats are going. does it feel like if you go up to about 2000 rpms at say 30mph it takes a noticable amount of time to come back down. could be clogged cats if so. cats also would explain surging. Id have it checked out. When the cats went in my E50 there was a symptom of the car acting like a manual transmission surging and bucking (not hard), like when you floor it and let up at low speed in a manual.
Othe possibility is some sort of EGR problem, maybe a vacuum leak in the emissions system.
Do you have any codes to read?
No codes coming up. I've had CATS go and the performance degradation is across the power band.
I think it's to do with the sensitivity of the fly by wire tech. It is only noticeable at 1000 RPM otherwise the car runs fantastic! Someone that does not drive the car regularly does not notice it when they drive it. MB and Independent tech's have driven it and not all pick it up. Those that have can not trouble shoot it.
bumps against 1000 rpm like maybe it wants to shift into next gear but computer is saying NO not yet - wait another 100 rpm.
I guess you'll find out whats wrong when it gets worse. If there is one thing I have learned about Mercedes, is if it seems out of the ordinary, it usually is. In a matter of time it will get worse.
I don't think its a electronics characteristic, my car doesn't do it and its old with high miles.
I would definitely look for vaccuum leaks, egr problem, exhaust leak.
Linear Mode
